The first time I heard of Nature is Brutal, it was in the context of cat necrophilia. See, I had friends over to grill sausages in the backyard, and the conversation turned to feral cats. My yard has a pretty stable community of feral cats that, during the day, cuddle up cutely in chairs. At night, they turn into monsters. I hear them hiss and growl — sometimes so loud that their noises enter my dreams, turning them into nightmares. And so we got into an argument about what the cats were fighting about, territory or sex.
One of my friends was saying that the males were fighting over females, adding that cats do weird things for sex. That was when he took out his phone and showed me this GIF of feral cats mounting a dead cat. In other words, cat necrophilia. The GIF was my introduction to Nature is Brutal. I was immediately hooked.